U.S. patent application number 15/177574 was filed with the patent office on 2017-12-14 for turbolink: method and apparatus for controlling lnput/output signaling speed.
This patent application is currently assigned to International Business Machines Corporation. The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Mitch GUSAT, Thomas TOIFL.
Application Number | 20170359266 15/177574 |
Document ID | / |
Family ID | 60574175 |
Filed Date | 2017-12-14 |
United States Patent
Application |
20170359266 |
Kind Code |
A1 |
GUSAT; Mitch ; et
al. |
December 14, 2017 |
Turbolink: Method and Apparatus for Controlling lnput/Output
Signaling Speed
Abstract
Embodiments of the present invention may provide improved
handling of communication characteristics, such as burstiness,
latency-sensitive applications, bandwidth-sensitive applications,
etc., to improve peak performance while not compromising other
characteristics, such as thermal design power of the input/output
chip packages. In an embodiment, in a control circuit that may be
connected to and control a data transmitter, a method of
transmitting data in a network may comprise receiving at least one
feed-forward signal from the data transmitter, receiving at least
one feedback signal from at least a first node of the network,
comparing the at least one feed-forward signal with at least one
threshold or condition, comparing the at least one feedback signal
with at least one threshold or condition, and generating a signal
indicating that a burst transmission should be started or
stopped.
Inventors: |
GUSAT; Mitch; (Langnau,
CH) ; TOIFL; Thomas; (Zurich, CH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Assignee: |
International Business Machines
Corporation
|
Family ID: |
60574175 |
Appl. No.: |
15/177574 |
Filed: |
June 9, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 43/0888 20130101;
H04L 47/266 20130101; H04L 47/30 20130101; H04L 43/0817 20130101;
H04L 43/0852 20130101; H04L 43/08 20130101; H04L 43/16 20130101;
H04L 47/29 20130101; H04L 47/11 20130101 |
International
Class: |
H04L 12/825 20130101
H04L012/825; H04L 12/26 20060101 H04L012/26; H04L 12/801 20130101
H04L012/801; H04L 12/835 20130101 H04L012/835 |
Claims
1. A method comprising: receiving at least one feed-forward signal
from a local or upstream data transmitter, receiving at least one
feedback signal from at least a next or downstream first node of a
network; comparing the at least one feed-forward signal with at
least one threshold or condition; comparing the at least one
feedback signal with at least one threshold or condition; and
generating a signal indicating that a burst transmission should be
started or stopped based on the comparison results.
2. The method of claim 1, wherein the data transmitter comprises
storage for data to be transmitted and the feed-forward signal from
the data transmitter comprises an indication of an occupancy of the
storage with data to be transmitted, a rate of change of the
occupancy of the storage with data to be transmitted, and a timer
indicating either a time that a first packet of the current burst
has waited for transmission, or a time since a last burst
transmission was performed.
3. The method of claim 2, wherein the feedback signal comprises a
near feedback signal from at least one network node at a network
location near the data transmitter, and a remote feedback signal
from at least one network node at a network location near a
destination of data transmission from the data transmitter, from
the destination of data transmission from the data transmitter, or
both.
4. The method of claim 3, further comprising: comparing the
occupancy of the storage with data to be transmitted to a first
threshold, a rate of change of the occupancy of the storage with
data to be transmitted to a second threshold, and a timer
indicating a time since a last burst transmission was performed
with a maximum delay time; and generating an indication that a
burst transmission should be started or stopped based on the
results of the comparisons.
5. The method of claim 4, further comprising: determining a status
of the near feedback signals and a status of the remote feedback
signals; and generating an indication that a burst transmission
should be started or stopped based on the status of the near
feedback signals and the status of the remote feedback signals.
6. The method of claim 5, wherein the near feedback signals
comprise at least one of a Link-Level Flow Control signal, a
PFC/CEE signal, a Credit/IB signal, a Credit/PCIe signal, a
Credit/Omnipath signal, a STOP/GO signal, and a responsive receive
buffer reservation signal.
7. The method of claim 6, wherein the remote feedback signals
comprise at least one of a direct multibit congestion notification
signal, a BECN/CNM signal, an indirect single bit congestion
notification signal a FECN/BECN signal, a CCA signal, a DC-TCP
signal, a DC-QCN/ECN signal, and a TCP/RED/ECN signal.
8. The method of claim 7, further comprising: receiving a signal
indicating a temperature of the data transmitter; comparing the
temperature of the data transmitter to a threshold temperature; and
generating an indication that a burst transmission should be
started or stopped based on whether the temperature of the data
transmitter exceeds the threshold temperature.
9. An apparatus comprising: at least one processor, and at least
one non-transitory memory including computer program code, the at
least one memory and the computer program code configured to, with
the at least one processor, cause the apparatus to: receive at
least one feed-forward signal from a local or upstream data
transmitter, receive at least one feedback signal from at least a
next or downstream first node of the network; and compare the at
least one feed-forward signal with at least one threshold or
condition, compare the at least one feedback signal with at least
one threshold or condition, and generate a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
10. The apparatus of claim 9, wherein the data transmitter
comprises storage for data to be transmitted and the feed-forward
signal from the data transmitter comprises an indication of an
occupancy of the storage with data to be transmitted, a rate of
change of the occupancy of the storage with data to be transmitted,
and a timer indicating either a time that a first packet of the
current burst has waited for transmission, or a time since a last
burst transmission was performed.
11. The apparatus of claim 10, wherein feedback signal comprises a
near feedback signal from at least one network node at a network
location near the data transmitter, and a remote feedback signal
from at least one network node at a network location near a
destination of data transmission from the data transmitter, from
the destination of data transmission from the data transmitter, or
both.
12. The apparatus of claim 11, wherein the at least one memory and
the computer program code are configured to, with the at least one
processor, further cause the apparatus to: compare the occupancy of
the storage with data to be transmitted to a first threshold, a
rate of change of the occupancy of the storage with data to be
transmitted to a second threshold, and a timer indicating a time
since a last burst transmission was performed with a maximum delay
time; and generate an indication that a burst transmission should
be started or stopped based on the results of the comparisons.
13. The apparatus of claim 12, wherein the at least one memory and
the computer program code are configured to, with the at least one
processor, further cause the apparatus to: determine a status of
the near feedback signals and a status of the remote feedback
signals; and generate an indication that a burst transmission
should be started or stopped based on the status of the near
feedback signals and the status of the remote feedback signals.
14. The apparatus of claim 13, wherein the near feedback signals
comprise at least one of a Link-Level Flow Control signal, a
PFC/CEE signal, a Credit/IB signal, a Credit/PCIe signal, a
Credit/Omnipath signal, a STOP/GO signal, and a responsive receive
buffer reservation signal.
15. The apparatus of claim 14, wherein the remote feedback signals
comprise at least one of a direct multibit congestion notification
signal, a BECN/CNM signal, an indirect single bit congestion
notification signal a FECN/BECN signal, a CCA signal, a DC-TCP
signal, a DC-QCN/ECN signal, and a TCP/RED/ECN signal.
16. The apparatus of claim 15, wherein the at least one memory and
the computer program code are configured to, with the at least one
processor, further cause the apparatus to: receive a signal
indicating a temperature of the data transmitter, compare the
temperature of the data transmitter to a threshold temperature; and
generate an indication that a burst transmission should be started
or stopped based on whether the temperature of the data transmitter
exceeds the threshold temperature.
17. A computer program product for transmitting data in a network,
the computer program product comprising a non-transitory computer
readable storage having program instructions embodied therewith,
the program instructions executable by a computer, to cause the
computer to perform a method comprising: receiving at least one
feed-forward signal from a local or upstream data transmitter,
receiving at least one feedback signal from at least a next or
downstream first node of the network; comparing the at least one
feed-forward signal with at least one threshold or condition;
comparing the at least one feedback signal with at least one
threshold or condition; and generating a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
18. The computer program product of claim 17, wherein the data
transmitter comprises storage for data to be transmitted and the
feed-forward signal from the data transmitter comprises an
indication of an occupancy of the storage with data to be
transmitted, a rate of change of the occupancy of the storage with
data to be transmitted, and a timer indicating either a time that a
first packet of the current burst has waited for transmission, or a
time since a last burst transmission was performed.
19. The computer program product of claim 18, wherein feedback
signal comprises a near feedback signal from at least one network
node at a network location near the data transmitter, and a remote
feedback signal from at least one network node at a network
location near a destination of data transmission from the data
transmitter, from the destination of data transmission from the
data transmitter, or both.
20. The computer program product of claim 19, further comprising
program instructions for: comparing the occupancy of the storage
with data to be transmitted to a first threshold, a rate of change
of the occupancy of the storage with data to be transmitted to a
second threshold, and a timer indicating a time since a last burst
transmission was performed with a maximum delay time; and
generating an indication that a burst transmission should be
started or stopped based on the results of the comparisons.
21-24. (canceled)
Description
BACKGROUND
[0001] The present invention relates to techniques for controlling
input/output signaling speed of network elements in
telecommunications networks with varying usage levels.
[0002] This section is intended to provide a background or context
to the invention disclosed below. The description herein may
include concepts that could be pursued, but are not necessarily
ones that have been previously conceived, implemented or described.
Therefore, unless otherwise explicitly indicated herein, what is
described in this section is not prior art to the description in
this application and is not admitted to be prior art by inclusion
in this section.
[0003] Many packet-based telecommunications networks exhibit bursty
or inconsistent traffic levels. Typically, a network may be
relatively empty when handling average or typical levels of
traffic. However, the same network may suffer congestion when
handling peak levels of traffic. The issue may be especially severe
in the environment of a data center, such as a cloud datacenter
that may host diverse applications, mixing workloads that require
small predictable latency with others requiring large sustained
throughput. For example, many cloud or distributed computing
networks may be under-utilized, having average link utilizations of
5-20%, with many typically under 10% average utilization. For
example, such underused links could become potential `donors` from
a thermal TDP perspective. These same, or other, often
under-utilized resources may occasionally become overbooked--hence
potential TDP `borrowers/receivers` that need, e.g., 110-200%
faster TRANSMISSION/TX rates for limited periods--to avoid being
hotspots or bottlenecks during brief congestive traffic events that
may have significant financial consequences on users of the
network, such as datacenter tenants and operators. This may lead to
more over-provisioning and average under-utilizations, while still
not solving the congestion during peak utilization.
[0004] Further, network traffic, such as that involved in cloud
datacenter or other datacenter applications, may be becoming
increasingly bursty due to the increasing usage of bursty
applications. For example, applications themselves may be becoming
increasingly bursty. Likewise, new processors may support interrupt
coalescing, in which interrupt processing is delayed until a
certain amount of processing is pending, which may lead to larger
bursts of traffic when the interrupts are finally processed.
Further, much network traffic may involve relatively small, but
frequent, units of network traffic, but may be very latency
sensitive.
[0005] Conventional schemes for handling bursty traffic may operate
relatively slowly and may interfere with the peak traffic and may
compromise performance agreements. A need arises for a technique
that may provide improved handling of communication
characteristics, such as burstiness, latency-sensitive
applications, bandwidth-sensitive applications, etc., to improve
peak performance while not compromising other characteristics, such
as thermal design power of the input/output chip packages.
SUMMARY
[0006] This section is intended to include examples and is not
intended to be limiting.
[0007] Embodiments of the present invention may provide improved
handling of communication characteristics, such as burstiness,
latency-sensitive applications, bandwidth-sensitive applications,
etc., to improve peak performance while not compromising other
characteristics, such as thermal design power of the input/output
chip packages. For example, embodiments of the present invention
may provide fast operation with cross-layer control inputs,
improved control lags and congestion controls, and may enable new
datacenter and high-performance computing techniques.
[0008] In an embodiment of the present invention, in a control
circuit that may be connected to and control a data transmitter, a
method of transmitting data in a network may comprise receiving at
least one feed-forward signal from a local or upstream data
transmitter, receiving at least one feedback signal from at least a
next or downstream first node of the network, comparing the at
least one feed-forward signal with at least one threshold or
condition, comparing the at least one feedback signal with at least
one threshold or condition, and generating a signal indicating that
a burst transmission should be started or stopped based on the
comparison results.
[0009] In an embodiment, the data transmitter may comprise storage
for data to be transmitted and the feed-forward signal from the
data transmitter may comprise an indication of an occupancy of the
storage with data to be transmitted, a rate of change of the
occupancy of the storage with data to be transmitted, and a timer
indicating either a time that a first packet of the current burst
has waited for transmission, or a time since a last burst
transmission was performed. The feedback signal may comprise a near
feedback signal from at least one network node at a network
location near the data transmitter, and a remote feedback signal
from at least one network node at a network location near a
destination of data transmission from the data transmitter, from
the destination of data transmission from the data transmitter, or
both. The method may further comprise comparing the occupancy of
the storage with data to be transmitted to a first threshold, a
rate of change of the occupancy of the storage with data to be
transmitted to a second threshold, and a timer indicating a time
since a last burst transmission was performed with a maximum delay
time, and generating an indication that a burst transmission should
be started or stopped based on the results of the comparisons. The
method may further comprise determining a status of the near
feedback signals and a status of the remote feedback signals, and
generating an indication that a burst transmission should be
started or stopped based on the status of the near feedback signals
and the status of the remote feedback signals. The near feedback
signals may comprise at least one of a Link-Level Flow Control
signal, a PFC/CEE signal, a Credit/IB signal, a Credit/PCIe signal,
a Credit/Omnipath signal, a STOP/GO signal, and a responsive
receive buffer reservation signal. The remote feedback signals may
comprise at least one of a direct multibit congestion notification
signal, a BECN/CNM signal, an indirect single bit congestion
notification signal a FECN/BECN signal, a CCA signal, a DC-TCP
signal, a DC-QCN/ECN signal, and a TCP/RED/ECN signal. The method
may further comprise receiving a signal indicating a temperature of
the data transmitter, comparing the temperature of the data
transmitter to a threshold temperature, and generating an
indication that a burst transmission should be started or stopped
based on whether the temperature of the data transmitter exceeds
the threshold temperature.
[0010] In an embodiment of the present invention, an apparatus is
provided comprising: at least one processor; and at least one
non-transitory memory including computer program code, the at least
one memory and the computer program code configured to, with the at
least one processor, cause the apparatus to: receive at least one
feed-forward signal from a local or upstream data transmitter;
receive at least one feedback signal from at least a next or
downstream first node of the network; and compare the at least one
feed-forward signal with at least one threshold or condition,
compare the at least one feedback signal with at least one
threshold or condition, and generate a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
[0011] In an embodiment of the present invention, a computer
program product for transmitting data in a network, may comprise a
non-transitory computer readable storage having program
instructions embodied therewith, the program instructions
executable by a computer, to cause the computer to perform a method
that may comprise receiving at least one feed-forward signal from a
local or upstream data transmitter, receiving at least one feedback
signal from at least a next/downstream first node of the network,
comparing the at least one feed-forward signal with at least one
threshold or condition, comparing the at least one feedback signal
with at least one threshold or condition, and generating a signal
indicating that a burst transmission should be started or stopped
based on the comparison results.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The details of the present invention, both as to its
structure and operation, can best be understood by referring to the
accompanying drawings, in which like reference numbers and
designations refer to like elements.
[0013] FIG. 1 is an exemplary block diagram of an embodiment of a
communication network, in which embodiments of the present
invention may be implemented.
[0014] FIG. 2 is an exemplary process flow diagram of an embodiment
of a process of transmission control in the network shown in FIG.
1.
[0015] FIG. 3 is an exemplary block diagram of a computer system,
in which embodiments of processes involved in the system, method,
and computer program product described herein may be
implemented.
DETAILED DESCRIPTION
[0016] The word "exemplary" is used herein to mean "serving as an
example, instance, or illustration." Any embodiment described
herein as "exemplary" is not necessarily to be construed as
preferred or advantageous over other embodiments. All of the
embodiments described in this Detailed Description are exemplary
embodiments provided to enable persons skilled in the art to make
or use the invention and not to limit the scope of the invention
which is defined by the claims.
[0017] Embodiments of the present invention may provide improved
handling of communication characteristics, such as burstiness,
latency-sensitive applications, bandwidth-sensitive applications,
etc., to improve peak performance while not compromising other
characteristics, such as thermal design power of the input/output
chip packages. For example, embodiments of the present invention
may provide fast operation with cross-layer control inputs,
improved control lags and congestion controls, and may enable new
datacenter and high-performance computing techniques.
[0018] Communications in data centers is typically based on
networks running the TCP/IP set of protocols. Data centers may
contain a set of routers and switches that transport traffic
between the servers and to the outside world. Much of the
communications in such data centers is typically transmitted over
optical links, which may use opto-electronic chips for their
input/output (I/O) circuitry. Such opto-electronic chips typically
have a thermal budget or thermal design power (TDP), which is the
amount of heat generated by the circuitry of the chip that can be
dissipated by the chip packaging and cooling, without exceeding a
specified maximum temperature.
[0019] For opto-electronic chips with I/O circuitry, embodiments of
the present invention provide techniques to control the energy or
joint power usage of the chip, while also controlling the
performance, such as delay and throughput, using closed loop
control, such as feed-forward and feedback, with thermal
constraints. For example, embodiments may maximize the global chip
throughput and/or minimize the traffic Burst Completion Time,
subject to staying within the thermal budget or TDP envelope of the
chip. Such embodiments may, under the TDP constraints of a
transmitting chip package, maximize the amount of injected
communication traffic that is likely to be received at the
destination end while minimizing delays. Embodiments may use
multiple feedback and feed-forward control loops to control which
links/channels should have priority in finishing their
transmissions, before the entire chip overheats. Such control may
result in control over the timing of burst transmissions in a way
that use a typical or other suitable pulse width modulation
(PWM)-like scheme in combination with the methods hereby described
to control the transmission rates, and thus the link
speed/utilization, for example, between 0% and 200%, vs. the
nominal rated speed of 100%.
[0020] Some well-known terms and acronyms are used herein. For
clarity, these terms and acronyms are described herein. Link-Level
Flow Control (LL-FC) is a closed loop flow control method typical
typically used in Layer 2 networks. For example, Priority Flow
Control (PFC) as described in the 802.1Qbb standard, or the Credits
(CDT) method, used in, for example, Peripheral Component
Interconnect Express (PCIe), the InfiniBand Architecture (IBA),
etc.
[0021] Quantized Congestion Notification (QCN), as described in the
802.1Qau standard.
[0022] Congestion Notification Message (CNM), as used by QCN.
[0023] Datacenter Transmission Control Protocol (DC-TCP).
[0024] Remote Direct Memory Access (RDMA)
[0025] Datacenter Quantized Congestion Notification (DC-QCN).
[0026] Explicit_Congestion_Notification (ECN/RED).
[0027] Referring to FIG. 1, an example of a communication network
100, in which embodiments of the present invention may be
implemented, is shown. Network 100 may include one or more bursty
traffic sources 102, turbolink controller 104, a plurality of
network switches 106-1-106-K, and a network traffic destination
108. Bursty traffic sources 102 may include computer systems, such
as servers or other systems, which may generate bursty network
traffic 103 in inconsistent or changing patterns. Network switches
106-1-106-K may include any type of network node or packet
switching devices, such simple packet switches, managed packet
switches, network hubs, routers, layer-3 switches, multilayer
switches, etc. Traffic destination 108 may include computer
systems, such as servers or other systems, which may receive
network traffic. For clarity, only a single traffic path and set of
components is shown as an example in FIG. 1. A typical system may
include many such components and traffic paths, perhaps hundreds or
thousands in large data centers.
[0028] Turbolink controller 104 may receive bursty traffic 103 from
bursty traffic sources 102 and may control the rate and bandwidth
of transmission of this traffic out to the traffic path. Also shown
in FIG. 1 is control combining element 110. Control combining
element 110 may receive traffic feedback signals 112-1-112-K from
one or more network switches 106-1-106-K and from traffic feedback
signal 114 from traffic destination 108. Control combining element
110 may then provide a control signal to turbolink controller 104,
so that turbolink controller 104 may control the rate and bandwidth
of transmission of the traffic.
[0029] Feedback signals 112-1-112-K and 114 may include standard
traffic control signals, such as priority flow control (PFC),
Credit/CDT, QCN, CNM, Data Center Transmission Control Protocol
(DCTCP), DC-QCN, Explicit Congestion Notification (ECN/RED), etc.
Feedback signals 112-1-112-K and 114 may be input to control
combining element 110, which combines feedback signals 112-1-112-K
and 114 to generate a signal representing the state of the traffic
path through network switches 106-1-106-K, and traffic destination
108. Feedback signals 112-1-112-K and 114 may be divided into two
groups--feedback near "FbNear" and feedback remote "FbRemote".
[0030] Feedback near signals may be feedback signals from network
nodes located close in the traffic path to Turbolink controller
104, such as, in the example shown in FIG. 1, feedback signal 112-1
from switch 106-1. Examples of feedback near signals may include
Link-Level Flow Control (LL-FC) signals from the next hop
downstream, such as PFC/CEE, Credit/IB, Credit/PCIe,
Credit/Omnipath, STOP/GO, responsive receive buffer reservation in
Switch 106-1, etc. This signal may represent a binary value, and
may indicate the amount of credits available for the credit
schemes, or the transmit time for the other schemes, for the
current burst injection signal.
[0031] Feedback remote signals may be feedback signals from network
nodes located remotely in the traffic path from turbolink
controller 104, such as, in the example shown in FIG. 1, feedback
signal 112-K from switch 106-K and feedback signal 114 from traffic
destination 108. Examples of feedback remote signals may include
signals from any downstream node, such as direct (multibit)
congestion notifications, such as BECN/CNM as in QCN, or indirect
(single bit) FECN/BECN congestion notifications such as IB CCA,
DC-TCP, DC-QCN, TCP/RED/ECN, or a combination of multiple signals
of each type or of both types.
[0032] An additional input to control combining element 110 may be
feed-forward signal 116, which is generated from bursty traffic
from source 102 and may be applied to control combining element 110
with either positive sign 118 or negative sign 120. Examples of
feed-forward signals may include a local transmit queue occupancy
("x") and gradient or rate of change of the local transmit queue
occupancy ("x") (forming a vector {x,x'}) and a burst accumulation
timer ("Twait") indicating a time since a last burst transmission
was performed, which may be compared to a maximum delay before at
least a partial burst/container is injected in the traffic
stream.
[0033] FIG. 2 is an exemplary flow diagram of an embodiment of a
process 200 of transmission control in the network shown in FIG. 1.
It is best viewed in conjunction with FIG. 1. Process 200 begins
with 202 in which the feed-forward state of the traffic path is
checked. For example, new packet arrivals and their backlog in the
local queue may be sampled as x=occupancy and x'=gradient. In 204,
the local transmit queue occupancy x and gradient x' may be
compared with their respective thresholds "X" and "X'", and the
current burst accumulation time Twait with the maximum delay time.
If neither threshold nor the delay time have been exceeded, this
means that not enough burst packets are available yet, so the
system continues accumulating new packets. In 206, if either
threshold or the delay time have been exceeded, this means that
enough burst packets are waiting in the burst container, or the
delay per packet has been exceeded, then the burst transmit request
signal ("BurstTXRequest") is activated.
[0034] In 208, if BurstTXRequest is activated, then the feed-back
state of the traffic path is checked. This is done by, in 210,
checking the FbNear signal status, such as checking if LL-FC
signals 112-1 indicate a "GO" or transmit condition. For example,
if there are sufficient credits or PFC status is not STOP, then
next-hop reception is enabled. This is typically true in lossy
Ethernet operation, leading to a lack of LL-FC signals indicating a
GO or transmit condition, and likewise for a STOP condition.
[0035] In 212, the FbRemote signal status is checked, such as by
the Turbolink controller 104 snoops the xECN signals 114 arriving
at the transmit source 102. In 214, it is determined whether a
computed period exceeds the time the PWM has been on. The computed
period represents a simulation of simple low-pass filter, which,
for example, may integrate (sum) the ECN signal with a fixed RESET
period, which may equal the logical round trip time (RTT) delay,
link flight+SERDES+higher layer logical delay/time constant and/or
other time constants. In 216, the temperature of the die or chip of
the transmit circuitry may be determined and compared with a
maximum allowed temperature ("Tmax") or other temperatures under
the TDP envelope, so as to not exceed the thermal budget.
[0036] In 218, the burst transmission is performed until completed
or until one of the feedback conditions checked in 212-216
indicates that the burst transmission should be stopped. For
example, a stop indication may include, in 210, the FbNear signal
not indicating a GO condition, in 212, the xECN signals indicate a
stop condition, in 214, the computed period exceeds the PWM on
time, and in 216, the determined temperature exceeds Tmax.
[0037] In an embodiment, memory may be used to store the burst data
to be transmitted. The burst container size can be fixed or
adaptive, for example between 4 and 128 maximum transmission units
(MTUs), which for Ethernet, for example, is about 1550 bytes.
[0038] An exemplary block diagram of a computer system 300, in
which the embodiments of processes involved in the system, method,
and computer program product described herein may be implemented,
is shown in FIG. 3. Computer system 300 is typically a programmed
general-purpose computer system, such as an embedded processor,
system on a chip, personal computer, workstation, server system,
and minicomputer or mainframe computer. Computer system 300 may
include one or more processors (CPUs) 302A-302N, input/output
circuitry 304, network adapter 306, and memory 308. CPUs 302A-302N
execute program instructions in order to carry out the functions of
the present invention. Typically, CPUs 302A-302N are one or more
microprocessors, such as an INTEL PENTIUM processor. FIG. 3
illustrates an embodiment in which computer system 300 is
implemented as a single multi-processor computer system, in which
multiple processors 302A-302N share system resources, such as
memory 308, input/output circuitry 304, and network adapter 306.
However, the present invention also contemplates embodiments in
which computer system 300 is implemented as a plurality of
networked computer systems, which may be single-processor computer
systems, multi-processor computer systems, or a mix thereof.
[0039] Input/output circuitry 304 provides the capability to input
data to, or output data from, computer system 300. For example,
input/output circuitry may include input devices, such as
keyboards, mice, touchpads, trackballs, scanners, etc., output
devices, such as video adapters, monitors, printers, etc., and
input/output devices, such as, modems, etc. Network adapter 306
interfaces device 300 with a network 310. Network 310 may be any
public or proprietary LAN or WAN, including, but not limited to the
Internet.
[0040] Memory 308 stores program instructions that are executed by,
and data that are used and processed by, CPU 302 to perform the
functions of computer system 300. Memory 308 may include, for
example, electronic memory devices, such as random-access memory
(RAM), read-only memory (ROM), programmable read-only memory
(PROM), electrically erasable programmable read-only memory
(EEPROM), flash memory, etc., and electro-mechanical memory, such
as magnetic disk drives, tape drives, optical disk drives, etc.,
which may use an integrated drive electronics (IDE) interface, or a
variation or enhancement thereof such as enhanced IDE (EIDE) or
ultra-direct memory access (UDMA), or a small computer system
interface (SCSI) based interface, or a variation or enhancement
thereof such as fast-SCSI, wide-SCSI, fast and wide-SCSI, etc., or
Serial Advanced Technology Attachment (SATA), or a variation or
enhancement thereof or a fiber channel-arbitrated loop (FC-AL)
interface.
[0041] The contents of memory 308 vary depending upon the function
that computer system 300 is programmed to perform. However, one of
skill in the art would recognize that these routines, along with
the memory contents related to those routines, may be included on
one system, or may be distributed among a plurality of systems,
based on well-known engineering considerations. The present
invention contemplates any and all such arrangements.
[0042] In the example shown in FIG. 3, memory 308 may include
feed-forward routines 312, feedback routines 314, transmission
control routines 316, and operating system 318. Feed-forward
routines 312 may include routines to monitor the status of
feed-forward signals. Feedback routines 314 may include routines to
monitor the status of feedback signals. Transmission control
routines 316 may include routines to receive the results of the
monitoring of the feed-forward and the feedback signals and
generate signals to control the burst transmission. Operating
system 318 provides overall system functionality.
[0043] In an embodiment of the present invention, a system for
transmitting data in a network may comprise circuitry adapted to
receive at least one feed-forward signal from a local or upstream
data transmitter, circuitry adapted to receive at least one
feedback signal from at least a next/downstream first node of the
network, and circuitry adapted to compare the at least one
feed-forward signal with at least one threshold or condition,
compare the at least one feedback signal with at least one
threshold or condition, and generate a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
[0044] An example method may comprise: receiving at least one
feed-forward signal from a local or upstream data transmitter;
receiving at least one feedback signal from at least a next or
downstream first node of a network; comparing the at least one
feed-forward signal with at least one threshold or condition;
comparing the at least one feedback signal with at least one
threshold or condition; and generating a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
[0045] The data transmitter may comprise storage for data to be
transmitted and the feed-forward signal from the data transmitter
may comprise at least one of an indication of an occupancy of the
storage with data to be transmitted, a rate of change of the
occupancy of the storage with data to be transmitted, and a timer
indicating either a time that a first packet of the current burst
has waited for transmission, and a time since a last burst
transmission was performed. The feedback signal may comprise a near
feedback signal from at least one network node at a network
location near the data transmitter, and a remote feedback signal
from at least one network node at a network location near a
destination of data transmission from the data transmitter, from
the destination of data transmission from the data transmitter, or
both. The method may further comprise comparing the occupancy of
the storage with data to be transmitted to a first threshold, a
rate of change of the occupancy of the storage with data to be
transmitted to a second threshold, and a timer indicating a time
since a last burst transmission was performed with a maximum delay
time; and generating an indication that a burst transmission should
be started or stopped based on the results of the comparisons. The
method may further comprise: determining a status of the near
feedback signals and a status of the remote feedback signals; and
generating an indication that a burst transmission should be
started or stopped based on the status of the near feedback signals
and the status of the remote feedback signals. The near feedback
signals may be at least one of a Link-Level Flow Control signal, a
PFC/CEE signal, a Credit/IB signal, a Credit/PCIe signal, a
Credit/Omnipath signal, a STOP/GO signal, and a responsive receive
buffer reservation signal. The remote feedback signals comprise at
least one of a direct multibit congestion notification signal, a
BECN/CNM signal, an indirect single bit congestion notification
signal a FECN/BECN signal, a CCA signal, a DC-TCP signal, a
DC-QCN/ECN signal, and a TCP/RED/ECN signal. The method may further
comprise receiving a signal indicating a temperature of the data
transmitter; comparing the temperature of the data transmitter to a
threshold temperature; and generating an indication that a burst
transmission should be started or stopped based on whether the
temperature of the data transmitter exceeds the threshold
temperature.
[0046] An example embodiment may be provided in an apparatus
comprising at least one processor, and at least one non-transitory
memory including computer program code, the at least one memory and
the computer program code configured to, with the at least one
processor, cause the apparatus to: receive at least one
feed-forward signal from a local or upstream data transmitter;
receive at least one feedback signal from at least a next or
downstream first node of the network; and compare the at least one
feed-forward signal with at least one threshold or condition,
compare the at least one feedback signal with at least one
threshold or condition, and generate a signal indicating that a
burst transmission should be started or stopped based on the
comparison results.
[0047] The data transmitter may comprise storage for data to be
transmitted and the feed-forward signal from the data transmitter
comprises an indication of an occupancy of the storage with data to
be transmitted, a rate of change of the occupancy of the storage
with data to be transmitted, and a timer indicating either a time
that a first packet of the current burst has waited for
transmission, or a time since a last burst transmission was
performed. The feedback signal may comprise a near feedback signal
from at least one network node at a network location near the data
transmitter, and a remote feedback signal from at least one network
node at a network location near a destination of data transmission
from the data transmitter, from the destination of data
transmission from the data transmitter, or both. The at least one
memory and the computer program code may be configured to, with the
at least one processor, further cause the apparatus to: compare the
occupancy of the storage with data to be transmitted to a first
threshold, a rate of change of the occupancy of the storage with
data to be transmitted to a second threshold, and a timer
indicating a time since a last burst transmission was performed
with a maximum delay time; and generate an indication that a burst
transmission should be started or stopped based on the results of
the comparisons. The at least one memory and the computer program
code may be configured to, with the at least one processor, further
cause the apparatus to: determine a status of the near feedback
signals and a status of the remote feedback signals; and generate
an indication that a burst transmission should be started or
stopped based on the status of the near feedback signals and the
status of the remote feedback signals. The near feedback signals
may be at least one of a Link-Level Flow Control signal, a PFC/CEE
signal, a Credit/IB signal, a Credit/PCIe signal, a Credit/Omnipath
signal, a STOP/GO signal, and a responsive receive buffer
reservation signal. The remote feedback signals may be at least one
of a direct multibit congestion notification signal, a BECN/CNM
signal, an indirect single bit congestion notification signal a
FECN/BECN signal, a CCA signal, a DC-TCP signal, a DC-QCN/ECN
signal, and a TCP/RED/ECN signal.
[0048] The at least one memory and the computer program code may be
configured to, with the at least one processor, further cause the
apparatus to: receive a signal indicating a temperature of the data
transmitter; compare the temperature of the data transmitter to a
threshold temperature; and generate an indication that a burst
transmission should be started or stopped based on whether the
temperature of the data transmitter exceeds the threshold
temperature.
[0049] An example embodiment may be provided in a computer program
product for transmitting data in a network. The computer program
product may comprise a non-transitory computer readable storage
having program instructions embodied therewith, the program
instructions executable by a computer, to cause the computer to
perform a method comprising: receiving at least one feed-forward
signal from a local or upstream data transmitter, receiving at
least one feedback signal from at least a next or downstream first
node of the network; comparing the at least one feed-forward signal
with at least one threshold or condition; comparing the at least
one feedback signal with at least one threshold or condition; and
generating a signal indicating that a burst transmission should be
started or stopped based on the comparison results.
[0050] The data transmitter may comprise storage for data to be
transmitted and the feed-forward signal from the data transmitter
may comprise an indication of an occupancy of the storage with data
to be transmitted, a rate of change of the occupancy of the storage
with data to be transmitted, and a timer indicating either a time
that a first packet of the current burst has waited for
transmission, or a time since a last burst transmission was
performed. The feedback signal may be a near feedback signal from
at least one network node at a network location near the data
transmitter, and a remote feedback signal from at least one network
node at a network location near a destination of data transmission
from the data transmitter, from the destination of data
transmission from the data transmitter, or both. The computer
program product may further comprise program instructions for
comparing the occupancy of the storage with data to be transmitted
to a first threshold, a rate of change of the occupancy of the
storage with data to be transmitted to a second threshold, and a
timer indicating a time since a last burst transmission was
performed with a maximum delay time; and generating an indication
that a burst transmission should be started or stopped based on the
results of the comparisons. The computer program product may
further comprise program instructions for: determining a status of
the near feedback signals and a status of the remote feedback
signals; and generating an indication that a burst transmission
should be started or stopped based on the status of the near
feedback signals and the status of the remote feedback signals. The
near feedback signals may be at least one of a Link-Level Flow
Control signal, a PFC/CEE signal, a Credit/IB signal, a Credit/PCIe
signal, a Credit/Omnipath signal, a STOP/GO signal, and a
responsive receive buffer reservation signal. The remote feedback
signals may be at least one of a direct multibit congestion
notification signal, a BECN/CNM signal, an indirect single bit
congestion notification signal a FECN/BECN signal, a CCA signal, a
DC-TCP signal, a DC-QCN/ECN signal, and a TCP/RED/ECN signal. The
computer program may further comprise program instructions for:
receiving a signal indicating a temperature of the data
transmitter; comparing the temperature of the data transmitter to a
threshold temperature; and generating an indication that a burst
transmission should be started or stopped based on whether the
temperature of the data transmitter exceeds the threshold
temperature.
[0051] As shown in FIG. 3, the present invention contemplates
implementation on a system or systems that provide multi-processor,
multi-tasking, multi-process, and/or multi-thread computing, as
well as implementation on systems that provide only single
processor, single thread computing. Multi-processor computing
involves performing computing using more than one processor.
Multi-tasking computing involves performing computing using more
than one operating system task. A task is an operating system
concept that refers to the combination of a program being executed
and bookkeeping information used by the operating system. Whenever
a program is executed, the operating system creates a new task for
it. The task is like an envelope for the program in that it
identifies the program with a task number and attaches other
bookkeeping information to it. Many operating systems, including
Linux, UNIX.RTM., OS/2.RTM., and Windows.RTM., are capable of
running many tasks at the same time and are called multitasking
operating systems. Multi-tasking is the ability of an operating
system to execute more than one executable at the same time. Each
executable is running in its own address space, meaning that the
executables have no way to share any of their memory. This has
advantages, because it is impossible for any program to damage the
execution of any of the other programs running on the system.
However, the programs have no way to exchange any information
except through the operating system (or by reading files stored on
the file system). Multi-process computing is similar to
multi-tasking computing, as the terms task and process are often
used interchangeably, although some operating systems make a
distinction between the two.
[0052] The present invention may be a system, a method, and/or a
computer program product at any possible technical detail level of
integration. The computer program product may include a computer
readable storage medium (or media) having computer readable program
instructions thereon for causing a processor to carry out aspects
of the present invention. The computer readable storage medium can
be a tangible device that can retain and store instructions for use
by an instruction execution device.
[0053] The computer readable storage medium may be, for example,
but is not limited to, an electronic storage device, a magnetic
storage device, an optical storage device, an electromagnetic
storage device, a semiconductor storage device, or any suitable
combination of the foregoing. A non-exhaustive list of more
specific examples of the computer readable storage medium includes
the following: a portable computer diskette, a hard disk, a random
access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), a static
random access memory (SRAM), a portable compact disc read-only
memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a
floppy disk, a mechanically encoded device such as punch-cards or
raised structures in a groove having instructions recorded thereon,
and any suitable combination of the foregoing. A computer readable
storage medium, as used herein, is not to be construed as being
transitory signals per se, such as radio waves or other freely
propagating electromagnetic waves, electromagnetic waves
propagating through a waveguide or other transmission media (e.g.,
light pulses passing through a fiber-optic cable), or electrical
signals transmitted through a wire.
[0054] Computer readable program instructions described herein can
be downloaded to respective computing/processing devices from a
computer readable storage medium or to an external computer or
external storage device via a network, for example, the Internet, a
local area network, a wide area network and/or a wireless network.
The network may comprise copper transmission cables, optical
transmission fibers, wireless transmission, routers, firewalls,
switches, gateway computers, and/or edge servers. A network adapter
card or network interface in each computing/processing device
receives computer readable program instructions from the network
and forwards the computer readable program instructions for storage
in a computer readable storage medium within the respective
computing/processing device.
[0055] Computer readable program instructions for carrying out
operations of the present invention may be assembler instructions,
instruction-set-architecture (ISA) instructions, machine
instructions, machine dependent instructions, microcode, firmware
instructions, state-setting data, configuration data for integrated
circuitry, or either source code or object code written in any
combination of one or more programming languages, including an
object oriented programming language such as Smalltalk, C++, or the
like, and procedural programming languages, such as the "C"
programming language or similar programming languages. The computer
readable program instructions may execute entirely on the user's
computer, partly on the user's computer, as a stand-alone software
package, partly on the user's computer and partly on a remote
computer or entirely on the remote computer or server. In the
latter scenario, the remote computer may be connected to the user's
computer through any type of network, including a local area
network (LAN) or a wide area network (WAN), or the connection may
be made to an external computer (for example, through the Internet
using an Internet Service Provider). In some embodiments,
electronic circuitry including, for example, programmable logic
circuitry, field-programmable gate arrays (FPGA), or programmable
logic arrays (PLA) may execute the computer readable program
instructions by utilizing state information of the computer
readable program instructions to personalize the electronic
circuitry, in order to perform aspects of the present
invention.
[0056] Aspects of the present invention are described herein with
reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems), and computer program products
according to embodiments of the invention. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer readable
program instructions.
[0057] These computer readable program instructions may be provided
to a processor of a general purpose computer, special purpose
computer, or other programmable data processing apparatus to
produce a machine, such that the instructions, which execute via
the processor of the computer or other programmable data processing
apparatus, create means for implementing the functions/acts
specified in the flowchart and/or block diagram block or blocks.
These computer readable program instructions may also be stored in
a computer readable storage medium that can direct a computer, a
programmable data processing apparatus, and/or other devices to
function in a particular manner, such that the computer readable
storage medium having instructions stored therein comprises an
article of manufacture including instructions which implement
aspects of the function/act specified in the flowchart and/or block
diagram block or blocks.
[0058] The computer readable program instructions may also be
loaded onto a computer, other programmable data processing
apparatus, or other device to cause a series of operational steps
to be performed on the computer, other programmable apparatus or
other device to produce a computer implemented process, such that
the instructions which execute on the computer, other programmable
apparatus, or other device implement the functions/acts specified
in the flowchart and/or block diagram block or blocks.
[0059] The flowchart and block diagrams in the Figures illustrate
the architecture, functionality, and operation of possible
implementations of systems, methods, and computer program products
according to various embodiments of the present invention. In this
regard, each block in the flowchart or block diagrams may represent
a module, segment, or portion of instructions, which comprises one
or more executable instructions for implementing the specified
logical function(s). In some alternative implementations, the
functions noted in the blocks may occur out of the order noted in
the Figures. For example, two blocks shown in succession may, in
fact, be executed substantially concurrently, or the blocks may
sometimes be executed in the reverse order, depending upon the
functionality involved. It will also be noted that each block of
the block diagrams and/or flowchart illustration, and combinations
of blocks in the block diagrams and/or flowchart illustration, can
be implemented by special purpose hardware-based systems that
perform the specified functions or acts or carry out combinations
of special purpose hardware and computer instructions.
[0060] Although specific embodiments of the present invention have
been described, it will be understood by those of skill in the art
that there are other embodiments that are equivalent to the
described embodiments. Accordingly, it is to be understood that the
invention is not to be limited by the specific illustrated
embodiments, but only by the scope of the appended claims.
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